Improvement in constructing field-fortifications



UNrren STATES PATENT OFFICE.

PIERRE JAMAIN, OF BORDEAUX, FRANCE, ASSIGNOR TO HIMSELF AND JAMES M. TRIPPE, OF ORANGE, NEW JERSEY.

IMPROVEMENT IN CONSTRUCTING FIELD-FORTIFICATIONS.

Specification forming part of Letters Patent No. L10,213, dated October 6, 1863.

To all whom t may concern: A

Be it known that I, PIERRE JAMAIN, of Bordeaux, in the Empire of France, have invented a new and useful Improvement in Field-Fortiiications and other Earth-Works;

f and I do hereby declare that the following is of the hollow wooden voussoirs which constitute an important element of my invention. Fig. 3 is a longitudinal sect-ion of the voussoir in its folded up or portable condition. Fig. 4

is an end view corresponding with Fig. 3.

Similar letters ot' reference indicate corresponding parts in the several figures.

This invention consists in the employment, in the construction of field-fortifications and other military' or engineering works, of light boxes of wood, or other suitable material, made in the form of voussoirs, and capable of being folded up to make them portable, so that each may be carried by a soldier behind his knapsack without inconvenience, or that they may be packed and carried in any other manner without occupying much room.

To enable others skilled in the art to make and use my invention, l will proceed to describe its construction and operation.

A A, Fig. 1, are the boxes or hollow voussoirs, made of thin wooden boards or of sheet metal. rIhese may be open on the side, which forms a portion of the interior of the arch, and are so represented. To form the arch these voussoirs or boxes are built over suitable vcentering-frames, B, as shown in Fig. l, in the same manner as in building an arch of stone or other materials. When the arch has been built, the earth is piled upon it to any suitable depth, and the centering-frames removed.

T0 form a caseinated held-fortification a trench is to be first dug of a width equal to the intended outside span of the arch, and of a depth about equal to the intended height of the arch, and of any length, and the hollow voussoirs or boxes are built up to form the arch on the bottom of this trench. The earth is then lled in to the trench and piled up in @he arch in the form of an embankment of any height sufficient to protect the arch from the enemys projectiles.

At every place where a gun-port is required one or more of the voussoirs is omitted from the arch, as shown at r in Fig. l, and an embrasure, s, is formed in the earth outside of this port, the top of the embrasure being formed by fascines t t or other means.

Figs. 2, 3, and 4 illustratate fully the construction of the boxes or hollow voussoirs to enable them to be folded up and carried by soldiers. I propose to make them either of wooden boards of about from three-eighths (l) to half an inch thick, or of tin plate or other sheetiron of a length of from eighteen (18) inches to two (2) feet, of a width across the face from twelve (l2) to fourteen (14) inches, and of a depthl from back to front of from live (5) to six (6) inches. The face-piece a is furnished with narrow riged rims b b along its upper and lower edges, to which the top and bottom pieces, c c, are hinged by hinges d d in such a manner as to be capable of folding inward, as shown in Fig. 4. rI-he end pieces, e e, are attached to the face-piece a by hinges h h, in such a manner as to fold within the top and bottom pieces, c c, close against the inner surface of the face-piece, as shown in Fig. 3, and a center supporting piece or brace, f, arranged between the top and bottom pieces, is hinged by hinges t' to a cleat, g, which is secured across the inner surface of the face-piece a.

In folding up the box or voussoir the end pieces, e e, are rst folded up,the piece f then folded over onto one of the pieces e, as shown in Fig. 3, and the side pieces folded one up'on another over the piece f.

"When the box or voussoir is required to be used,it is easily unfolded, and when unfolded is as well adapted to the purpose for which it is intended as though its parts were all rigidly secured together. l

I/Vhat I claim as my invention, and desire to secure by Letters Patent, is-

The employment, in the construction of eldfortifications and embankments, of portable voussoirs of wood, or other material, made to fold up, substantially as herein. described.

PIERRE JAMAIN.

Witnesses:

P. D. ROUG, H. P. LIVERMORE, 

